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| using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Drawing;
using OpenTK;
using OpenTK.Graphics;
using OpenTK.Graphics.OpenGL;
using OpenTK.Input;
namespace LightTest
{
internal static class Program
{
static void Main()
{
using (var app = new RenderEngine())
{
app.Run();
}
}
}
internal class RenderEngine : GameWindow
{
private readonly int _width = 800;
private readonly int _height = 600;
private readonly List<Light> _lights = new List<Light>();
private readonly List<Block> _blocks = new List<Block>();
private int _fragmentShader;
private int _shaderProgram;
private Random r = new Random();
public RenderEngine() : base(800, 600, GraphicsMode.Default, "2D lighting test", GameWindowFlags.FixedWindow) { }
protected override void OnLoad(EventArgs e)
{
SetUpObjects();
Initialize();
}
protected override void OnClosing(CancelEventArgs cancelEventArgs)
{
Cleanup();
}
protected override void OnRenderFrame(FrameEventArgs e)
{
GL.Clear(ClearBufferMask.ColorBufferBit);
foreach (var light in _lights) // Для каждого источника света подрубаем stencil буфер
{
GL.ColorMask(false, false, false, false);
GL.StencilFunc(StencilFunction.Always, 1, 1);
GL.StencilOp(StencilOp.Keep, StencilOp.Keep, StencilOp.Replace);
foreach (var block in _blocks) // Тут мы должны рассчитать и отрисовать тень для stencil буфера
{
Vector2[] vertices = block.GetVertices();
for (int i = 0; i < vertices.Length; i++)
{
Vector2 currentVertex = vertices[i];
Vector2 nextVertex = vertices[(i + 1) % vertices.Length];
Vector2 edge = Vector2.Subtract(nextVertex, currentVertex);
Vector2 normal = new Vector2(edge.Y, -edge.X);
Vector2 lightToCurrent = Vector2.Subtract(currentVertex, light.Location);
if (Vector2.Dot(normal, lightToCurrent) > 0)
{
Vector2 tmp1;
Vector2.Subtract(ref nextVertex, ref light.Location, out tmp1);
Vector2 point1 = Vector2.Add(currentVertex, Vector2.Multiply(tmp1, 500));
Vector2 tmp2;
Vector2.Subtract(ref nextVertex, ref light.Location, out tmp2);
Vector2 point2 = Vector2.Add(nextVertex, Vector2.Multiply(tmp2, 500));
GL.Begin(PrimitiveType.Quads);
GL.Vertex2(currentVertex.X, currentVertex.Y);
GL.Vertex2(point1.X, point1.Y);
GL.Vertex2(point2.X, point2.Y);
GL.Vertex2(nextVertex.X, nextVertex.Y);
GL.End();
}
}
}
GL.StencilOp(StencilOp.Keep, StencilOp.Keep, StencilOp.Keep); // Отрубаем stencil буфер
GL.StencilFunc(StencilFunction.Equal, 0, 1);
GL.ColorMask(true, true, true, true);
GL.UseProgram(_shaderProgram); // И отрисовываем свет через шейдер там, где буфер пуст
GL.Uniform2(GL.GetUniformLocation(_shaderProgram, "lightLocation"), light.Location.X, _height - light.Location.Y);
GL.Uniform3(GL.GetUniformLocation(_shaderProgram, "lightColor"), light.Red, light.Green, light.Blue);
GL.Enable(EnableCap.Blend);
GL.BlendFunc(BlendingFactor.One, BlendingFactor.One);
GL.Begin(PrimitiveType.Quads);
GL.Vertex2(0, 0);
GL.Vertex2(0, _height);
GL.Vertex2(_width, _height);
GL.Vertex2(_width, 0);
GL.End();
GL.Disable(EnableCap.Blend);
GL.UseProgram(0);
GL.Clear(ClearBufferMask.StencilBufferBit);
}
GL.Color3(0, 0, 0);
foreach (var block in _blocks) // Тут рисуем блоки
{
GL.Begin(PrimitiveType.Quads);
foreach (var vertex in block.GetVertices())
{
GL.Vertex2(vertex.X, vertex.Y);
}
GL.End();
}
SwapBuffers();
base.OnRenderFrame(e);
}
protected override void OnKeyDown(KeyboardKeyEventArgs e)
{
if (e.Key == Key.Escape) Close();
}
protected override void OnMouseWheel(MouseWheelEventArgs mouseWheelEventArgs)
{
if (mouseWheelEventArgs.Delta > 1) // Крутится вперёд
{
_lights[0].Red++;
_lights[0].Green++;
_lights[0].Blue++;
}
if (mouseWheelEventArgs.Delta < 1) // Крутится назад
{
_lights[0].Red--;
_lights[0].Green--;
_lights[0].Blue--;
}
}
protected override void OnMouseMove(MouseMoveEventArgs mouseMoveEventArgs)
{
_lights[0].Location.X = mouseMoveEventArgs.Position.X;
_lights[0].Location.Y = mouseMoveEventArgs.Position.Y - 40; // Погрешность на заголовок окна (WindowBorder.Fixed)
}
private void SetUpObjects() // Тут накидывем свет и блоки на сцену
{
int lightCount = 1 + r.Next(5);
int blockCount = 1 + r.Next(10);
for (int i = 1; i <= lightCount; i++)
{
Vector2 location = new Vector2(r.Next(_width), r.Next(_height));
_lights.Add(new Light(location, r.Next(10), r.Next(10), r.Next(10)));
}
for (int i = 1; i <= blockCount; i++)
{
int lwidth = 50;
int lheight = 50;
int x = r.Next(_width - lwidth);
int y = r.Next(_height - lheight);
_blocks.Add(new Block(x, y, lwidth, lheight));
}
}
private void Initialize() // Тут вся инициализация
{
_shaderProgram = GL.CreateProgram();
_fragmentShader = GL.CreateShader(ShaderType.FragmentShader);
const string fragmentShaderSource =
@"#version 420 core
uniform vec2 lightLocation;
uniform vec3 lightColor;
void main()
{
float distance = length(lightLocation - gl_FragCoord.xy);
float attenuation = 1.0 / distance;
vec4 color = vec4(attenuation, attenuation, attenuation, pow(attenuation, 3)) * vec4(lightColor, 1);
gl_FragColor = color;
}";
GL.ShaderSource(_fragmentShader, fragmentShaderSource);
GL.CompileShader(_fragmentShader);
int res;
GL.GetShader(_fragmentShader, ShaderParameter.CompileStatus, out res);
if (res == 0)
Console.WriteLine("Чекай шейдер, он не компилится.");
GL.AttachShader(_shaderProgram, _fragmentShader);
GL.LinkProgram(_shaderProgram);
GL.ValidateProgram(_shaderProgram);
GL.MatrixMode(MatrixMode.Projection);
GL.LoadIdentity();
GL.Ortho(0, _width, _height, 0, 1, -1);
GL.MatrixMode(MatrixMode.Modelview);
GL.Enable(EnableCap.StencilTest);
GL.ClearColor(0.0f, 0.0f, 0.0f, 0.0f);
}
private void Cleanup()
{
GL.DeleteShader(_fragmentShader);
GL.DeleteProgram(_shaderProgram);
}
}
} |
(
